Hybrid multi-air conditioning system and method for controlling a hybrid multi-air conditioning system

ABSTRACT

A hybrid multi-air conditioning system and a method for controlling a hybrid multi-air conditioning system are provided. The hybrid multi-air conditioning system may include a hot water supply unit including a hot water supply heat exchanger that exchanges heat between refrigerant and water accommodated in a water tank and a first hot water supply expansion valve that blocks or allows refrigerant condensed in the hot water supply heat exchanger to flow through a first hot water supply discharge pipe; at least one indoor device installed indoors and including an indoor heat exchanger and at least one indoor expansion valve; an outdoor device connected to the at least one indoor device and the hot water supply unit through a refrigerant pipe and including an outdoor heat exchanger, a compressor, and an outdoor expansion valve; a second hot water supply discharge pipe having a first side branched from the first hot water supply discharge pipe, which connects the hot water supply heat exchanger and the indoor heat exchanger, and a second side that joins a first discharge pipe, which connects the compressor and the outdoor heat exchanger; and a second hot water supply expansion valve installed on the second hot water supply discharge pipe.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2022-0091269, filed in Korea on Jul. 22, 2022, which is hereby incorporated by reference in its entirety.

BACKGROUND 1 Field

A hybrid multi-air conditioning system and a method for controlling a hybrid multi-air conditioning system are disclosed herein.

2. Background

In general, a hybrid system capable of simultaneous cooling and hot water supply operations uses a plate heat exchanger, such as a hydro-kit, when using a water tank to firstly perform refrigerant-water heat exchange with an air-side cycle, and to secondly perform water-water heat exchange between the hydro-kit and the water tank. Related art Korean Patent Publication No. 10-2010-0023877, which is hereby incorporated by reference, discloses a heat pump type hot water supply device. When using a hydro-kit as in the related art, an amount of condensation heat on a refrigerant side can be controlled by a flow rate of water. However, if a refrigerant-side condensation heat exchanger is directly wound around a water tank, the condensation heat amount varies according to a water temperature inside of the water tank and a user's water consumption, so a control point of a water tank condenser changes. In addition, when a receiver is installed in a condenser, only low-pressure liquid refrigerant is sent to an evaporator, so that a sudden drop in low pressure can be prevented by an expansion valve of an indoor device during a cooling operation.

In the case of a hybrid system capable of simultaneous hot water supply and cooling operations, a water tank and an outdoor device side heat exchanger are operated by a condenser and are divided into two, expansion valves are installed at a water tank outlet and an outdoor device outlet, respectively, and refrigerant is sent to an indoor device-side expansion valve. The refrigerant discharged from each condenser must pass through two expansion valves until the refrigerant is changed from high pressure to low pressure, where if an opening of the expansion valve is too small, excessive pressure loss occurs and two-phase refrigerant enters the expansion valve. When a two-phase refrigerant enters the expansion valve, an evaporation temperature of the evaporator is greatly reduced, and an evaporation temperature reduction may cause cycle hunting and limit control entry.

In addition, in the case of the conventional hybrid multi-air conditioning system, there is a problem of damage to the compressor due to an increase in a condensation temperature on a water tank side and a decrease in cooling capacity due to a reduction in frequency of the compressor. Also, as a degree of supercooling at the water tank side was not secured, a two-phase refrigerant other than liquid refrigerant flowed into the indoor device, resulting in insufficient cooling capacity and an excessive drop in low pressure.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements, and wherein:

FIG. 1 is a schematic diagram of a hybrid multi-air conditioning system according to an embodiment;

FIG. 2 is a schematic diagram of the hybrid multi-air conditioning system of FIG. 1 ;

FIG. 3 is an operation diagram of the hybrid multi-air conditioning system of FIG. 2 during an independent cooling operation;

FIG. 4 is an operation diagram of the hybrid multi-air conditioning system of FIG. 2 during an independent heating operation;

FIG. 5 is an operation diagram of the hybrid multi-air conditioning system of FIG. 2 during an independent operation of hot water supply;

FIG. 6 is an operation diagram of the hybrid multi-air conditioning system of FIG. 2 during a heating and hot water supply operation;

FIG. 7 is an operation diagram of the hybrid multi-air conditioning system of FIG. 2 during cooling and hot water supply operations;

FIG. 8 is an operation diagram illustrating a state in which only the hot water supply heat exchanger operates as a condenser during cooling and hot water supply operations of the hybrid multi-air conditioning system of FIG. 2 ;

FIG. 9 is a control diagram of the hybrid multi-air conditioning system of FIG. 1 ; and

FIG. 10 is a flowchart of a method for controlling a hybrid multi-air conditioning system according to an embodiment.

DETAILED DESCRIPTION

Features of embodiments will become clear with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. However, the embodiments are not limited to the embodiments disclosed hereinafter and may be implemented in a variety of different forms.

Hereinafter, with reference to the accompanying drawings, embodiments are described as follows.

FIG. 1 is a schematic diagram of a hybrid multi-air conditioning system according to an embodiment. FIG. 2 is a schematic diagram of the hybrid multi-air conditioning system of FIG. 1 .

Referring to FIGS. 1 and 2 , hybrid multi-air conditioning system 100 according to an embodiment may include a hot water supply unit 30, at least one indoor device 20 for both heating and cooling, and an outdoor device 10 for both heating and cooling. The hot water supply unit 30 may include a water tank 31 that extends lengthwise in a vertical direction while storing water for hot water supply, a water circulation pipe that supplies water from outside to a bottom of the water tank 31 and discharges heated water to the outside through a top of the water tank 310, and a hot water supply heat exchanger 32 attached to an outside of the water tank 31 and coupled thereto to enable heat dissipation.

Heat exchange between the water tank 31 and the hot water supply heat exchanger 32 is performed by heat exchange between a refrigerant flowing through the hot water supply heat exchanger 32 and water inside of the water tank 31. The hot water supply heat exchanger 32 acts as a condenser that performs a heat dissipation function.

In the hot water supply heat exchanger 32, a pipe through which the refrigerant flows may be directly wound around an outer wall of the water tank 31 in a coil shape to increase a contact area, thereby exchanging heat. In addition, the hot water supply heat exchanger 32 has a hot water supply input pipe 34 connected to a second discharge pipe 42 of the outdoor device 10 and a first hot water supply discharge pipe 35 through which condensed liquid refrigerant flows after heat exchange with the water tank 31.

The first hot water supply discharge pipe 35 may be connected to a first node n1 that connects the indoor device 20, the outdoor device 10, and the hot water supply unit 30. A first hot water supply expansion valve 33 may be disposed in the first hot water supply discharge pipe 35 of the hot water supply heat exchanger 32.

The first hot water supply expansion valve 33 formed in a discharge portion of the hot water supply heat exchanger 32 may be an electronic expansion valve, adjust a flow rate of the refrigerant flowing through the pipe of the hot water supply heat exchanger 32, and allow the condensed refrigerant to flow into the outdoor device 10 or the indoor device 20. In this way, heat exchange is performed directly between the water and the refrigerant in the water tank 31 without a separate hydro kit, and thus, the heat exchange takes place directly, so that a heat exchange efficiency may be improved.

The indoor device 10 for both heating and cooling may include a compressor 13, an outdoor heat exchanger 11, an outdoor heat exchanger fan 12, and a switching means. The switching means includes a four-way valve 14 according to this embodiment. The compressor 13 may include a plurality of compressors 13 connected in parallel; however, embodiments are not limited thereto. An accumulator may be formed at an input end of the compressor 13. When there are a plurality of compressors 13, a first compressor may be an inverter compressor capable of varying a compression capacity of the refrigerant, and a second compressor may be a constant speed compressor having a constant compression capacity of the refrigerant.

A low-pressure connection pipe 46 connected to the indoor device 20 may be connected to an input pipe 45 of the compressor 13 via the four-way valve 14. First and second discharge pipes 42 and 43 may be connected to a discharge portion 41 of the compressor 13 as a high-pressure connection pipe. According to this embodiment, the first discharge pipe 43 allow discharged high-temperature and high-pressure gaseous refrigerant to flow into the outdoor heat exchanger 11. The second discharge pipe 42 allows the discharged high-temperature and high-pressure gaseous refrigerant to flow into the hot water supply unit 30 and is connected to the hot water supply heat exchanger 32.

The first discharge pipe 43 may pass through the four-way valve 14 and be connected to the outdoor heat exchanger 11. The second discharge pipe 42 may bypass refrigerant discharged from the compressor 13 without passing through the four-way valve 14 and be connected to the hot water supply heat exchanger 32.

The outdoor heat exchanger 11 may be connected to the four-way valve 14 through the first discharge pipe 43. In the outdoor heat exchanger 11, refrigerant is condensed or evaporated by heat exchange with outdoor air. In order to facilitate heat exchange, the outdoor device fan 12 introduces air into the outdoor heat exchanger 11. In the hybrid multi-air conditioning system 100 capable of heating and cooling and hot water supply, the outdoor heat exchanger 11 is used as a condenser during a cooling operation, and the outdoor heat exchanger 11 is used as an evaporator during a heating operation.

An outdoor expansion valve 17 may be installed on a liquid pipe connection pipe 44 that connects the outdoor heat exchanger 11 and the indoor device 20. The outdoor expansion valve 17 expands refrigerant during the heating operation. The outdoor expansion valve 17 expands refrigerant condensed in the plurality of indoor heat exchangers 21 during the heating operation before the refrigerant flows into the outdoor heat exchanger 11.

The four-way valve 14 may be provided in the discharge portion 41 of the compressor 13 and switch a flow path of refrigerant flowing in the outdoor device 10. The four-way valve 14 may switch the flow path of the refrigerant discharged from the compressor 13 according to hot water supply, cooling and heating operations of the hybrid multi-air conditioning system 100.

Such an outdoor device 10 for both heating and cooling may include a hot water supply valve 15 between the second discharge pipe 42 and the hot water supply input pipe 34 and a discharge valve 16 between the first discharge pipe 43 and the discharge portion 41 of the compressor 13. The hot water supply valve 15 and the discharge valve 16 may be solenoid valves that selectively operate to block or allow the refrigerant to flow as needed.

The hot water supply valve 15 and the discharge valve 16 do not need to operate in a hot water supply operation when the water temperature reaches the user's desired water temperature during cooling and hot water supply and heating and hot water supply operations. In addition, when the hot water valve 15 is closed, only the outdoor device 10 serves as a condenser during the cooling operation, and only the indoor device 20 serves as a condenser during the heating operation.

The outdoor device 10 may further include a supercooling device (not illustrated) on the liquid pipe connection pipe 44. The supercooling device may cool the refrigerant transferred to the indoor device 20 during the cooling operation.

The hybrid multi-air conditioning system 100 includes at least one indoor device 20. A plurality of indoor devices 20 for both heating and cooling may be connected to one outdoor device 10. For example, three indoor devices B1, B2, and B3 are illustrated in FIGS. 1 and 2 ; however, embodiments are not limited thereto.

Each of the indoor devices B1, B2, and B3 for both heating and cooling includes an indoor heat exchanger 21, an indoor expansion valve 22, and an indoor fan 23, respectively. As illustrated in FIG. 2 , when three indoor devices B1, B2, and B3 are installed, first, second, and third indoor heat exchangers 21, first, second, and third indoor expansion valves 22 and first, second, and third indoor device fans 23 are included. The first, second, and third indoor expansion valves 22 are installed on first, second, and third indoor connection pipes 26 that connect the first, second, and third indoor heat exchangers 21 and the first node n1. The first, second, and third indoor connection pipes 26 may be connected to the liquid pipe connection pipe 44 of the outdoor device 10 at the first node n1.

The indoor devices B1, B2, and B3 for both cooling and heating may be connected in parallel. Alternatively, the indoor devices B1, B2, and B3 for both cooling and heating may be connected in series.

The first, second, and third indoor devices B1, B2, and B3 for both cooling and heating may also be connected with low-pressure connection pipes 27 (46) through which the discharged refrigerant flows to the compressor 13.

The air conditioning system 100 according to an embodiment may further include a pressure sensor that measures a pressure of the refrigerant, a temperature sensor that measures a temperature of the refrigerant, and a strainer that removes foreign substances present in the refrigerant flowing through the refrigerant pipe.

In the hybrid multi-air conditioning system 100, when the outdoor device 10, the indoor device 20, and the hot water supply unit 30 act as condensers or evaporators according to operation modes, a separate refrigerant flow rate control device is not applied and it's function may be performed by opening the currently installed electronic expansion valve. In particular, the optimum refrigerant flow rate control is possible by controlling each electronic expansion valve by determining a superheating degree or supercooling degree through a plurality of temperature sensors formed in each electronic expansion valve.

More specifically, in the hybrid multi-air conditioning system 100, temperature control of the hot water supply unit 30 is performed in a state in which an amount of water cannot be controlled, and direct heat exchange is performed without a separate hydro kit, so that it is possible to determine whether two-phase refrigerant flows into the evaporator by determining the superheating degree of the discharged refrigerant. Therefore, it is possible to block the two-phase refrigerant by controlling the opening of the first hot water supply expansion valve 33 according to whether the two-phase refrigerant flows in.

The hybrid multi-air conditioning system 100 according to an embodiment is capable of an independent cooling operation, an independent heating operation, a cooling and hot water supply operation, a heating and hot water supply operation, and an independent hot water supply operation. In addition, during cooling and hot water supply operations, a heat exchanger operating as a condenser may be variously set according to the temperature of the water in the water tank 31 and the cooling load.

During the cooling operation, the outdoor heat exchanger 11 operates as a condenser. In addition, for hot water heating, the hot water supply heat exchanger 32 also operates as a condenser.

In order to increase cooling and hot water supply efficiency and prevent damage to the compressor 13, the outdoor heat exchanger 11 or the hot water supply heat exchanger 32 operating as a condenser may be selected according to each situation. A hot water supply discharge pipe 36 having a first side which is branched from the first hot water supply discharge pipe 35 that connects the hot water supply heat exchanger 32 and the indoor heat exchanger 21, and a second side which is joined to the first discharge pipe 43 that connects the compressor 13 and the outdoor heat exchanger 11, and a second hot water supply expansion valve 37 installed on the second hot water discharge pipe 36 are included. The second hot water supply discharge pipe 36 may be branched from the first hot water supply discharge pipe 35 between the hot water supply heat exchanger 32 and the first hot water supply expansion valve 33 and may be joined to the first discharge pipe 43 between the four-way valve 14 and the outdoor heat exchanger 11.

A first temperature sensor 38 installed to detect a temperature of water in the water tank 31 may be included. Further, second temperature sensor 47 installed at a rear end (discharge end) of the compressor 13 to measure a temperature of the refrigerant may be further included. Furthermore, a first pressure sensor 48 installed at the rear end (discharge end) of the compressor 13 to measure a pressure of the refrigerant may be further included. The condensation temperature may be predicted through high-pressure information detected by the first pressure sensor 48.

Hereinafter, operation of the system according to each drive mode will be described.

FIG. 3 is an operation diagram of the hybrid multi-air conditioning system of FIG. 2 during an independent cooling operation. Referring to FIG. 3 , as the hot water supply operation is stopped during a cooling-only operation, only the outdoor heat exchanger 11 singly operates as a condenser.

At this time, the hot water supply valve 15 is closed and the discharge valve 16 is opened. Then, the first hot water supply expansion valve 33 and the second hot water supply expansion valve 37 are closed, and the outdoor expansion valve 17 and the indoor expansion valve 22 are opened. For reference, when a plurality of indoor expansion valves 22 is provided, only a portion of the indoor expansion valves 22 may be opened or all of the indoor expansion valves 22 may be opened according to an indoor environment.

More specifically, the refrigerant, which is in a high-temperature and high-pressure gaseous phase after the compressor 13 operates, passes through the discharge valve 16 and then passes through the four-way valve 14 to be sent to the outdoor heat exchanger 11. The high-pressure, high-temperature gaseous refrigerant sent to the outdoor heat exchanger 11, as described above, is condensed into a high-pressure liquid refrigerant by exchanging heat with outdoor air.

The condensed liquid refrigerant passes through the outdoor expansion valve 17, passes through the indoor expansion valve 22 of the indoor device 20 operating in the cooling operation at the first node n1 to be expanded, and then is transferred to the indoor heat exchanger 21 operating as the evaporator as a low-pressure refrigerant. After the low-pressure refrigerant enters the indoor device 20, the low-pressure refrigerant is evaporated through heat exchange with indoor air. Thus, an indoor space is cooled. Then, the low-temperature gaseous refrigerant discharged from the indoor heat exchanger 21 repeats the process of passing through the four-way valve 14 through the low-pressure connection pipe 46, flows into the input pipe 45 of the compressor 13, is introduced into the compressor 13 again, and is re-discharged as a high-pressure, high-temperature gaseous refrigerant.

At this time, the outdoor expansion valve 17 is fully open, and an opening degree of the indoor expansion valve 22 may be adjusted according to a target indoor temperature and a cooling load.

Through this process, indoor cooling may proceed in a state in which hot water supply is stopped.

FIG. 4 is an operation diagram of the hybrid multi-air conditioning system of FIG. 2 during an independent heating operation. Referring to FIG. 4 , in the case of an independent heating operation, the hot water supply operation is stopped, and the outdoor heat exchanger 11 operates as an evaporator. In addition, the indoor heat exchanger 21 operates as a condenser.

At this time, the hot water supply valve 15 is closed and the discharge valve 16 is closed. Then, the first hot water supply expansion valve 33 and the second hot water supply expansion valve 37 are closed, and the outdoor expansion valve 17 and the indoor expansion valve 22 are opened.

For reference, when a plurality of indoor expansion valves 22 is provided, only some of the indoor expansion valves 22 may be opened according to the indoor environment, or all of the indoor expansion valves 22 may be opened.

More specifically, the refrigerant, which is in the a high-temperature and high-pressure gaseous phase after the compressor 13 operates, passes through the discharge valve 16 and then passes through four-way valve 14 to be sent to the indoor heat exchanger 21. The high-pressure, high-temperature gaseous refrigerant sent to the indoor heat exchanger 21, as described above, is condensed into a high-pressure liquid refrigerant through heat exchange with indoor air. In this process, heating of an indoor space proceeds.

The condensed high-pressure liquid refrigerant passes through the indoor expansion valve 22 and is sent to a side of the outdoor expansion valve 17 at the first node n1. In addition, the low-temperature two-phase refrigerant passing through the outdoor expansion valve 17 is transferred to the outdoor heat exchanger 11 operating as an evaporator.

The low-temperature two-phase refrigerant introduced into the outdoor heat exchanger 11 exchanges heat with outdoor air and evaporates into a low-temperature gaseous refrigerant. Thereafter, the low-temperature gaseous refrigerant discharged from the outdoor heat exchanger 11 repeats the process of passing through the four-way valve 14, flows into the input pipe 45 of the compressor 13, is introduced into the compressor 13 again, and is re-discharged as the high-pressure and high-temperature gaseous refrigerant.

At this time, the outdoor expansion valve 17 is fully open, and the opening degree of the indoor expansion valve 22 may be adjusted according to a target indoor temperature and heating load.

Through this process, in a state in which hot water supply is stopped, indoor heating may proceed.

FIG. 5 is an operation diagram of the hybrid multi-air conditioning system of FIG. 2 during an independent operation of hot water supply. The independent hot water supply operation is performed when only hot water supply is requested without cooling or heating.

At this time, the hot water supply valve 15 is opened and the discharge valve 16 is closed. In addition, the first hot water supply expansion valve 33 and the outdoor expansion valve 17 are opened, and the second hot water supply expansion valve 37 and the indoor expansion valve 22 are closed.

More specifically, the refrigerant that is in a high-pressure gaseous phase after the compressor 13 operates is sent to the hot water supply heat exchanger 32 operating as a condenser through the second discharge pipe 42 and the hot water supply valve 15. The high-temperature, high-pressure gaseous refrigerant sent to the hot water supply heat exchanger 32, as described above, exchanges heat with the water inside of the water tank 31 to heat the water inside of the water tank 31 and is condensed into a high-pressure liquid phase.

The condensed high-pressure liquid refrigerant passes through the first hot water supply expansion valve 33 and is transferred from the first node n1 to the outdoor expansion valve 17 side. Then, the refrigerant expanded into the low-temperature two-phase refrigerant in the outdoor expansion valve 17 repeats the process of passing through the outdoor heat exchanger 11 operating as an evaporator, passing through the four-way valve 14, and flowing into the input pipe 45 of the compressor 13, is introduced into the compressor 13 again, and is re-discharged as a high-pressure, high-temperature gaseous refrigerant.

Through this process, only the hot water supply operation may be performed in a state in which indoor cooling or heating is stopped.

FIG. 6 is an operation diagram of the hybrid multi-air conditioning system of FIG. 2 during a heating and hot water supply operation. When the heating and hot water operation is requested, all valves except for the second hot water supply expansion valve 37 are opened. In other words, the second hot water supply expansion valve 37 is closed, the hot water supply valve 15 and the discharge valve 16 are opened, and the first hot water supply expansion valve 33, the outdoor expansion valve 17, and the indoor expansion valve 22 are opened. In addition, the outdoor heat exchanger 11 operates as an evaporator, and the indoor heat exchanger 21 operates as a condenser.

For reference, when a plurality of indoor expansion valves 22 is provided, only some of the indoor expansion valves 22 may be opened according to the indoor environment, or all of the indoor expansion valves 22 may be opened.

More specifically, after the compressor 13 operates, a portion of the high-temperature and high-pressure gaseous refrigerant passes through the discharge valve 16 and then passes through the four-way valve 14 and is sent to the indoor heat exchanger 21, and the remaining portion passes through the hot water supply valve 15 and is sent to the hot water supply heat exchanger 32. The high-pressure, high-temperature refrigerant sent to the indoor heat exchanger 21 and the hot water supply heat exchanger 32, as described above, is condensed into a high-pressure liquid refrigerant while exchanging heat with the indoor air to heat the indoor space, or exchanges heat with water inside of the water tank 31 to heat the water inside of the water tank 31 and is condensed into a high-pressure liquid refrigerant.

The condensed high-pressure liquid refrigerant passes through the indoor expansion valve 22 and the first hot water supply expansion valve 33, respectively, meets at the first node n1 and is transferred to the outdoor heat exchanger 11 through the outdoor expansion valve 17 of the outdoor device 10 which operates as an evaporator at the first node n1. The refrigerant introduced into the outdoor heat exchanger 11 repeats the process of being evaporated by heat exchange with outdoor air, passing through the four-way valve 14 through the first discharge pipe 43, and then flowing to the input pipe 45 of the compressor 13, is introduced into the compressor 13 again, and is re-discharged as a high-pressure, high-temperature gaseous refrigerant.

At this time, the opening degree of the indoor expansion valve 22 may be adjusted according to a target indoor temperature and heating load.

Through this process, the hot water supply operation and indoor heating may be performed simultaneously.

FIG. 7 is an operation diagram of the hybrid multi-air conditioning system of FIG. 2 during cooling and hot water supply operations. When cooling and hot water supply operations of the hybrid multi-air conditioning system according to an embodiment start, the flow of refrigerant proceeds as illustrated in FIG. 7 . When the cooling and hot water supply operation starts, the heat exchangers 11 and 32 of the outdoor device 10 and the hot water supply unit 30 operate as condensers, and the heat exchanger 21 of the indoor device 20 operates as an evaporator.

When the cooling and hot water supply operation is requested, all valves except for the first hot water supply expansion valve 33 and the discharge valve 16 are opened. In other words, the first hot water supply expansion valve 33 and the discharge valve 16 are closed, the hot water supply valve 15 is opened, and the second hot water supply expansion valve 37, the outdoor expansion valve 17, and the indoor expansion valve 22 are opened.

For reference, when a plurality of indoor expansion valves 22 is provided, only some of the indoor expansion valves 22 may be opened according to the indoor environment, or all of the indoor expansion valves 22 may be opened.

More specifically, a refrigerant that is in a high-pressure gaseous phase after the compressor 13 operates passes through the hot water supply valve 15 and is sent to the hot water supply heat exchanger 32. The high-pressure, high-temperature refrigerant sent to the hot water supply heat exchanger 32, as described above is condensed into a liquid phase by heat exchange with the water inside of the water tank 31 to heat water inside of the water tank 31. Then, the condensed liquid refrigerant passes through the second hot water supply expansion valve 37, is sent to the outdoor heat exchanger 11, and is further condensed by exchanging heat with outdoor air.

The condensed liquid refrigerant passes through the outdoor expansion valve 17 and the first hot water supply expansion valve 33, passes through the indoor expansion valve 22 of the indoor device 20 which operates in a cooling mode, and thus, is transferred to the indoor heat exchanger 21 as low-pressure refrigerant. After entering the indoor device 20, the low-pressure refrigerant evaporates by exchanging heat with indoor air, passes through the four-way valve 14 through the low-pressure connection pipe 46 while cooling the indoor air, and enters the input pipe 45 of the compressor 13 and is introduced into the compressor 13 again.

In the case of embodiments, in the hot water supply and cooling operation mode, through at least one information of the water temperature detected by the first temperature sensor 38, the refrigerant discharge temperature detected by the second temperature sensor 47, and the discharge pressure and the condensation temperature detected by the first pressure sensor 48, it is possible to select the outdoor heat exchanger 11 or the hot water supply heat exchanger 32. In addition, the outdoor heat exchanger 11 or the hot water supply heat exchanger 32 to be used as the condenser may be selected through an operating frequency (Hz) of the compressor 13.

At this time, only the outdoor heat exchanger 11 may singly operate as a condenser. Further, only the hot water supply heat exchanger 32 may singly operate as a condenser. Furthermore, both the outdoor heat exchanger 11 and the hot water supply heat exchanger 32 may operate as condensers.

For example, when only the outdoor heat exchanger 11 is singly operated as a condenser, the hot water supply valve 15 is closed and the discharge valve 16 is opened, similarly to the independent cooling operation. Then, the first hot water supply expansion valve 33 and the second hot water supply expansion valve 37 are closed, and the outdoor expansion valve 17 and the indoor expansion valve 22 are opened. At this time, even in the cooling and hot water supply operation, only the outdoor heat exchanger 11 operates as a condenser.

More specifically, the refrigerant, which is in a high-pressure gaseous phase after the compressor 13 operates, passes through the discharge valve 16 and then passes through the four-way valve 14 to be sent to the outdoor heat exchanger 11. The high-pressure, high-temperature refrigerant sent to the outdoor heat exchanger 11, as described above, is condensed through heat exchange with outdoor air.

The condensed liquid refrigerant passes through the outdoor expansion valve 17 and passes through the indoor expansion valve 22 of the indoor device 20 performing a cooling operation at the first node n1 and then is transferred to the indoor heat exchanger 21 as low-pressure refrigerant.

After entering the indoor device 20, the low-pressure refrigerant repeats a process of evaporating by exchanging heat with indoor air, passing through the four-way valve 14 through the low-pressure connection pipe 46 while cooling the indoor air, and flowing into the input pipe 45 of the compressor 13, is introduced into the compressor 13 again, and is re-discharged as a high-pressure, high-temperature gaseous refrigerant.

FIG. 8 is an operation diagram illustrating a state in which only the hot water supply heat exchanger operates as a condenser during cooling and hot water supply operations of the hybrid multi-air conditioning system of FIG. 2 . As another example, when only the hot water supply heat exchanger 31 singly operates as a condenser, the flow of refrigerant proceeds as illustrated in FIG. 8 .

In other words, the hot water supply valve 15 is opened and the discharge valve 16 is closed. In addition, the first hot water supply expansion valve 33 and the indoor expansion valve 22 are opened, the second hot water supply expansion valve 37 and the outdoor expansion valve 17 are closed, and only the hot water supply heat exchanger 32 operates as a condenser.

For reference, when a plurality of indoor expansion valves 22 is provided, only some of the indoor expansion valves 22 may be opened according to the indoor environment, or all of the indoor expansion valves 22 may be opened.

More specifically, refrigerant, which is in a high-pressure gas phase after the compressor 13 operates, is sent to the hot water supply heat exchanger 32 operating as a condenser through the second discharge pipe 42 and the hot water supply valve 15. The high-temperature, high-pressure gaseous refrigerant sent to the hot water supply heat exchanger 32, as described above, exchanges heat with the water inside of the water tank 31 to heat the water inside of the water tank 31 and is condensed into a high-pressure liquid phase.

The condensed high-pressure liquid refrigerant passes through the first hot water supply expansion valve 33 and is transferred from the first node n1 to the indoor expansion valve 22 side. Then, the refrigerant that has passed through the indoor expansion valve 22 repeats the process of passing through the indoor heat exchanger 21, passing through the four-way valve 14, flowing into the input pipe 45 of the compressor 13, is introduced into the compressor 13, again, and is re-discharged as a high-pressure, high-temperature gaseous refrigerant.

Through this process, even during cooling and hot water supply operations, only the hot water supply operation may be performed singly. In other words, only the hot water supply heat exchanger 32 may operate as a condenser.

FIG. 9 is a control diagram of the hybrid multi-air conditioning system of FIG. 1 . The hybrid multi-air conditioning system 100 may include a controller 50. The controller 50 may receive values measured from the first temperature sensor 38, the second temperature sensor 47, and the first pressure sensor 48. In other words, the controller 50 may receive the water temperature measured by the first temperature sensor 38, the discharge temperature measured by the second temperature sensor 47, the discharge pressure measured by the first pressure sensor 48, or a condensation temperature value determined from the discharge pressure.

For reference, the controller 50 may calculate a discharge superheating degree based on the discharge temperature measured by the second temperature sensor 47, the discharge pressure measured by the first pressure sensor 48, or the condensation temperature value determined from the discharge pressure. In addition, the controller 50 may receive operation frequency (Hz) information of the compressor.

The controller 50 may open and close hot water supply valve 15, discharge valve 16, first hot water supply expansion valve 33, second hot water supply expansion valve 37, outdoor expansion valve 17, and indoor expansion valve 22 or may adjust an opening degree thereof. Further, the controller 50 may adjust an open position of the four-way valve 14, and may adjust whether or not the respective fans 12 and 23 operate and a number of revolutions per unit time.

The controller 50 may control whether or not the heater 60 described hereinafter operates and an output thereof. In addition, the controller 50 may control the operating frequency (Hz) and capacity of the compressor 13.

Hereinafter, a heat exchanger operating as a condenser according to each situation in a hot water supply and cooling operation mode will be described.

For example, in the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank 31 is a preset or predetermined reference temperature or less and a cooling load is lower than preset or predetermined reference value, it is a situation in which a refrigerant cycle for cooling is unnecessary, and only a refrigerant cycle for hot water supply is required. Accordingly, the controller 50 opens the first hot water supply expansion valve 33 and closes the second hot water supply expansion valve 37.

In addition, in the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank 31 is the predetermined reference temperature or less and the cooling load is lower than the predetermined reference value, this is a situation in which a refrigerant cycle for cooling is unnecessary, and only a refrigerant cycle for hot water supply is required. Therefore, only the hot water supply heat exchanger 32 is controlled to operate as a condenser. In other words, at this time, the refrigerant flows as illustrated in FIG. 8 . The hot water supply valve 15 is opened and the discharge valve 16 is closed. In addition, the first hot water supply expansion valve 33 and the indoor expansion valve 22 are opened, the second hot water supply expansion valve 37 and the outdoor expansion valve 17 are closed, and only the hot water supply heat exchanger 32 operates as a condenser.

As another example, in the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank 31 is a predetermined reference temperature or less and the cooling load is higher than a predetermined reference value, this is a situation in which a refrigerant cycle for cooling is required, and also, a refrigerant cycle for hot water supply is required. Accordingly, the controller 50 opens the second hot water supply expansion valve 37 and closes the first hot water supply expansion valve 33.

In addition, in the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank 31 is the predetermined reference temperature or less and the cooling load is higher than the predetermined reference value, this is a situation in which a refrigerant cycle for cooling is required, and also, a refrigerant cycle for hot water supply is required. Therefore, both the hot water supply heat exchanger 32 and the outdoor heat exchanger 11 are controlled to operate as condensers.

In other words, at this time, the refrigerant flows as illustrated in FIG. 7 . That is, the hot water supply valve 15 is opened and the discharge valve 16 is closed. Then, the second hot water supply expansion valve 37, the outdoor expansion valve 17, and the indoor expansion valve 22 are opened, and the first hot water supply expansion valve 33 is closed, so that the heat exchangers 11 and 32 of the outdoor device 10 and the hot water supply unit 30 operate as condensers, and the heat exchanger 21 of the indoor device 20 operates as an evaporator.

In addition, in the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank 31 is a predetermined reference temperature or less and the cooling load is higher than the predetermined reference value, a refrigerant cycle for cooling is required, and although the refrigerant cycle for hot water supply is selectively required, the controller 50 opens the second hot water supply expansion valve 37 and closes the first hot water supply expansion valve 33.

In addition, in the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank 31 is the predetermined reference temperature or more and the cooling load is higher than the predetermined reference value, a refrigerant cycle for cooling is required, and although the refrigerant cycle for the hot water supply is selectively required, the controller 50 operates both the hot water supply heat exchanger 32 and the outdoor heat exchanger 11 as condensers.

However, in the hot water supply and cooling operation mode, even if the temperature of the water accommodated in the water tank 31 is the predetermined reference temperature or more and the cooling load is higher than the predetermined reference value, the controller 50, according to the discharge superheating degree of the compressor 13, opens the first hot water supply expansion valve 33 or the second hot water supply expansion valve 37.

In the hot water supply and cooling operation mode, even if the temperature of the water accommodated in the water tank 31 is the predetermined reference temperature or more and the cooling load is higher than the predetermined reference value, when the discharge superheating degree of the compressor 13 is smaller than a preset or predetermined reference superheat, as illustrated in FIG. 8 , the controller 50 operates the hot water supply heat exchanger 31 singly as a condenser.

In other words, the hot water supply valve 15 is opened and the discharge valve 16 is closed. In addition, the first hot water supply expansion valve 33 and the indoor expansion valve 22 are opened, the second hot water supply expansion valve 37 and the outdoor expansion valve 17 are closed. Thus, the controller 50 operates only the hot water supply heat exchanger 32 as a condenser.

As another example, in the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank 31 is a predetermined reference temperature or more and the cooling load is lower than a predetermined reference value, the controller 50 operates only the outdoor heat exchanger 11 as a condenser. In other words, as illustrated in FIG. 3 , only the outdoor heat exchanger 11 may singly operate as a condenser so that the hot water supply operation is stopped, and the independent cooling operation is performed.

At this time, the hot water supply valve 15 is closed and the discharge valve 16 is opened. Then, the first hot water supply expansion valve 33 and the second hot water supply expansion valve 37 are closed, and the outdoor expansion valve 17 and the indoor expansion valve 22 are opened.

In addition, in the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank 31 is the predetermined reference temperature or more and the cooling load is lower than the predetermined reference value, the water tank 31 may be heated with a separately provided heater instead of the refrigerant cycle.

In the hot water supply and cooling operation mode, a heat exchanger operating as a condenser according to each situation is referred to Table 1 below.

TABLE 1 case Water Temperature Cooling Load Condenser 1 Reference Reference Value or Hot Water Supply Temperature or less less Heat Exchanger 2 Reference Exceeding Hot Water Supply Temperature or less Reference Value Heat Exchanger and Outdoor Heat Exchanger 3 Exceeding Exceeding Hot Water Supply Reference Reference Value Heat Exchanger and Temperature (Exceeding Outdoor Heat Discharge Super Exchanger heating Degree Reference) 4 Exceeding Exceeding Hot Water Supply Reference Reference Value Heat Exchanger Temperature (Discharge Super heating Degree Reference or less) 5 Exceeding Reference Value or Outdoor Heat Reference less Exchanger Temperature

FIG. 10 is a flowchart of a method for controlling a hybrid multi-air conditioning system according to an embodiment. As described above, the hybrid multi-air conditioning system according to embodiments, during cooling and hot water supply operations, according to the water temperature and cooling load, may use the hot water supply heat exchanger 32 or the outdoor heat exchanger 11 as an independent condenser or may use the hot water supply heat exchanger 32 and the outdoor heat exchanger 11 disposed in series together as a condenser.

In addition, a heat exchanger to operate as a condenser may be selected by measuring the discharge temperature, condensation temperature, and water temperature through the temperature sensor, and the pressure sensor, for example, and reflecting the operating frequency Hz of the compressor.

In general, as the compressor determines an evaporation temperature according to a required cooling load, and the condensation temperature is relatively low when the cooling load is low, it is difficult to secure discharge a superheating degree capable of supplying hot water. This worsens as the area of the condenser increases. In addition, when only the hot water supply heat exchanger 32 is used as a condenser, the condensation temperature may be further increased and a waste heat recovery rate is higher than when the hot water supply heat exchanger 32 and the outdoor heat exchanger 11 are used together as the condenser.

However, when the water temperature of the water tank 31 is too high in a cooling low load, because there is a limit to the increase in condensation temperature even if the condenser is reduced by using only the hot water supply heat exchanger 32 as a condenser, it is necessary to heat the water tank 31 using a separate heater 60 to supply hot water and perform the cooling operation alone.

If the cooling load is large, it is necessary to increase a size of the condenser because the required condensing capacity also increases. In this case, the hot water supply heat exchanger 32 and the outdoor heat exchanger 11 are used together as the condenser.

In addition, as the water temperature in the water tank 31 is relatively higher than the outdoor temperature and the target water temperature is also generally 50 to 60° C., a series structure in which the water tank 31 is mainly heated by the discharge superheating degree is used.

When both the water temperature in the water tank 31 and the cooling load are low during the cooling and hot water supply operation (for example: water temperature <40° C., compressor frequency <30 Hz), only the hot water supply heat exchanger 32 is singly used as a condenser. Thus, the condenser waste heat recovery rate may be increased.

When the cooling load is high during cooling and hot water supply operations, as the condensing capacity is insufficient only with the hot water supply heat exchanger 32, the hot water supply heat exchanger 32 and the outdoor heat exchanger 11 are used together as a condenser. However, when the outdoor temperature is lower than the set temperature, because the discharge superheating degree is secured too low and it is difficult to secure the hot water supply capacity, at this time, only the hot water supply heat exchanger 32 is used as a condenser.

In addition, when the temperature of the water in the water tank 31 is high even though the cooling load is low, hot water supply is impossible. Therefore, only the outdoor heat exchanger 11 is used as a condenser to perform the independent cooling operation, and hot water supply may be performed by a separate heater 60.

Referring to FIG. 10 , the hybrid multi-air conditioning system according to an embodiment selects heat exchangers 11 and 32 to be used as condensers by calculating the discharge superheating degree with the compressor discharge temperature and condensation temperature during the cooling and hot water supply operation and reflecting the information of the calculated discharge superheating degree, the water temperature inside of the water tank, and the operating frequency Hz of the compressor.

First, after entering the cooling and hot water supply operation mode, the cooling load is determined by comparing the operating frequency of the compressor with a reference value (S11). For example, if the operating frequency of the compressor 13 is less than 30 Hz, it may be determined that the cooling load is low, and conversely, if the operating frequency of the compressor 13 is 30 Hz or more, it may be determined that the cooling load is high.

In (S11), if the operating frequency of the compressor 13 is less than 30 Hz, it is determined that the cooling load is low, and the temperature of the water in the water tank 31 is detected (S12). In (S12), if the water temperature in the water tank 31 is less than the reference temperature, the water temperature in the water tank 31 is low in a low cooling load situation, so the hot water supply heat exchanger 32 is singly used as a condenser (S15).

In other words, in a situation in which the water temperature of the water tank 31 is low as described above, it is determined that it is possible to implement a condenser for cooling and hot water supply only with the hot water supply heat exchanger 32, and in order to increase the condenser waste heat recovery rate, the hot water supply heat exchanger 32 is singly used alone as a condenser.

At this time, the flow of the refrigerant proceeds as illustrated in FIG. 8 . In other words, the hot water supply valve 15 is opened and the discharge valve 16 is closed. In addition, the first hot water supply expansion valve 33 and the indoor expansion valve 22 are opened, the second hot water supply expansion valve 37 and the outdoor expansion valve 17 are closed, and only the hot water supply heat exchanger 32 operates as a condenser.

In step (S12), if the water temperature of the water tank 31 is the reference temperature or more, as the water temperature in the water tank 31 is high in the case of a low cooling load, only the outdoor heat exchanger 11 may be controlled to operate as a condenser (S14). In other words, as illustrated in FIG. 3 , the outdoor heat exchanger 11 alone may operate as a condenser so that the hot water supply operation is stopped, and the independent cooling operation is performed.

At this time, the hot water supply valve 15 is closed and the discharge valve 16 is opened. Then, the first hot water supply expansion valve 33 and the second hot water supply expansion valve 37 are closed, and the outdoor expansion valve 17 and the indoor expansion valve 22 are opened.

As described above, in the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank 31 is the predetermined reference temperature or more, and when the cooling load is lower than the predetermined reference value, the water tank 31 is heated by a separately provided heater, not by a refrigerant cycle. In other words, when the hot water supply heat exchanger 32 is used as a condenser in a situation in which the cooling load is low and the water temperature in the water tank 31 is the reference temperature or more, it may be difficult to form a normal cycle while reaching the condensation temperature increase limit.

Therefore, in a situation in which the cooling load is low and the water temperature in the water tank 31 is the reference temperature or more, it is switched to the single cooling mode, and only the outdoor heat exchanger 11 is singly used as a condenser, and in the case of the water tank 31, hot water is supplied using a separate heater attached to the inside.

On the other hand, in (S11), if the operating frequency of the compressor 13 is 30 Hz or more, it is determined that the cooling load is high, and the discharge temperature of the compressor and the condensation temperature information are used to calculate the discharge superheating degree (S13). In (S13), if the discharge superheating degree is less than the reference temperature, the process proceeds to (S12).

In addition, in (S12), if the temperature of the water in the water tank 31 is less than the reference temperature, the temperature of the water in the water tank 31 is low in the cooling low load situation, so the hot water supply heat exchanger 32 is used singly as a condenser (S15).

In addition, in (S12), if the water temperature of the water tank 31 is the reference temperature or more, only the outdoor heat exchanger 11 may be controlled to operate as a condenser (S14).

On the other hand, in (S13), if the discharge superheating degree is the reference temperature or more, the hot water supply heat exchanger 32 and the outdoor heat exchanger 11 are used as condensers together (S16). At this time, the hot water supply valve 15 is opened and the discharge valve 16 is closed. Then, the first hot water supply expansion valve 33 is closed, and the second hot water supply expansion valve 37, the outdoor expansion valve 17, and the indoor expansion valve 22 are opened.

As described above, when the operation frequency of the compressor is 30 Hz or more in the hot water supply and cooling operation mode, the condensation load increases, and thus, the size of the condenser may be insufficient only with the water tank. Therefore, both the hot water supply heat exchanger 32 and the outdoor heat exchanger 11 are used as condensers.

However, if the discharge superheating degree is not secured 5° C. or more (if outdoor temperature is too low), after checking whether the water temperature is 40° C. or less, if it is 40° C. or less, the hot water supply heat exchanger 32 is operated singly through valve control as a condenser.

If the water temperature is 40° C. or more, the outdoor heat exchanger (11) is used alone as a condenser, and the water in the water tank (31) is heated with a separate heater because the risk of high pressure limitation is high at the cooling load of 30 Hz or higher. Conversely, if the discharge superheating degree of 5° C. or higher can be secured when the compressor is 30 Hz or higher, the hot water supply heat exchanger 32 and the outdoor heat exchanger 11 are continuously used as condensers.

In the above method, values of the operating frequency of the compressor, which is the standard for determining the cooling load, the water temperature which is the standard, and the value of the discharge superheating degree which is the standard may be changed according to circumstances.

According to embodiments described herein, there is an advantage in that a heat exchanger that heats a water tank and a heat exchanger for an outdoor device are disposed in series, so that hot water supply performance may be secured as the refrigerant flow rate in the discharge superheating degree section increases. Further, in the case of a heat exchanger for an outdoor device, supercooling is secured, so that cycles may be implemented more stably and the condensation temperature can be lowered.

Furthermore, there is an advantage that only the heat exchanger for the water tank may be operated as a condenser or only the heat exchanger for the outdoor device may be operated as a condenser. Also, there is an advantage in that the heat exchanger for the water tank and the heat exchanger for the outdoor device may simultaneously operate as condensers. In other words, in the case of embodiments, there is an advantage in that the condenser can be selected and operated according to each situation.

In addition, there is an advantage in that, in the case of embodiments, during the cooling and hot water operation, when the cooling load and water temperature are high, the water tank heat exchanger and the outdoor device heat exchanger are disposed in series to be used as condensers at the same time, and when the cooling load and water temperature are low, waste heat recovery efficiency may be further increased by using only the water tank-side heat exchanger as a condenser. During the cooling and hot water supply operation, the condensation temperature is lowered to increase cooling performance and efficiency of hot water supply, and thus, it is advantageous to prevent damage to the compressor, and there is an advantage in that a waste heat recovery rate and efficiency of hot water supply may be increased under low load conditions or a low water temperature in the water tank.

There is an advantage in that heat exchange efficiency is improved by directly exchanging heat between the refrigerant and water by winding a coil capable of exchanging heat between the refrigerant and water around the water tank. In addition, there is an advantage in that the inflow of abnormal refrigerant may be prevented by controlling an optimum degree of supercooling degree by adjusting the opening degrees of the first hot water supply expansion valve and the outdoor expansion valve without installing a separate receiver. Also, there is an advantage in that simultaneous operation of hot water supply and cooling as well as operation of hot water supply and heating are possible.

Embodiments disclosed herein provide a hybrid multi-air conditioning system in which a heat exchanger for heating a water tank and a heat exchanger for an outdoor device are disposed in series to increase a flow rate of refrigerant in a superheating degree section, thereby securing hot water supply performance. Embodiments disclosed herein further provide a hybrid multi-air conditioning system capable of more stably realizing a cycle and lowering a condensation temperature by securing supercooling of a heat exchanger for an outdoor device.

Embodiments disclosed herein provide a hybrid multi-air conditioning system capable of operating only a heat exchanger for a water tank as a condenser or operating only a heat exchanger for an outdoor device as a condenser. In addition, embodiments disclosed herein provide a hybrid multi-air conditioning system in which a water tank may firstly perform heat exchange by directly exchanging heat between refrigerant and water.

Embodiments disclosed herein provide a hybrid multi-air conditioning system that may prevent two-phase refrigerant from entering by adjusting an opening of a first hot water supply expansion valve and an outdoor expansion valve without installing a separate receiver, and thus, controlling the optimal degree of supercooling. In addition, embodiments disclosed herein provide a hybrid multi-air conditioning system capable of simultaneous operation of hot water supply and cooling as well as operation of hot water supply and heating.

In order to solve the above problems, a multiple air conditioning system according to embodiments disclosed herein may include a hot water supply unit including a hot water supply heat exchanger that exchanges heat between the refrigerant and water accommodated in the water tank and a first hot water supply expansion valve that is closed or opened to allow refrigerant condensed to flow from the hot water supply heat exchanger; at least one indoor device installed indoors and including an indoor heat exchanger and an indoor expansion valve; and an outdoor device connected to the indoor device and the hot water supply unit through a refrigerant pipe and including an outdoor heat exchanger, a compressor, and an outdoor expansion valve.

The multiple air conditioning system may further include a second hot water supply discharge pipe having one or a first side branched from the first hot water supply discharge pipe connecting the hot water supply heat exchanger and the indoor heat exchanger and the other or a second side joining the first discharge pipe connecting the compressor and the outdoor heat exchanger.

The multiple air conditioning system may include a second hot water supply expansion valve installed on the second hot water supply discharge pipe.

The hybrid multi-air conditioning system may further include a first temperature sensor installed to detect the water temperature in the water tank. The hybrid multi-air conditioning system may further include a second temperature sensor installed at a rear end of the compressor. The hybrid multi-air conditioning system may also include a first pressure sensor installed at the rear end of the compressor.

The hot water supply heat exchanger may wind the outer wall of the water tank in a coil form and may exchange heat between the refrigerant and water while the refrigerant flows into the inside of the hot water supply heat exchanger.

The outdoor device may include a hot water supply valve for flowing the compressed refrigerant from the compressor to the hot water supply unit; and a discharge valve for flowing the compressed refrigerant from the compressor to the outdoor heat exchanger or the indoor heat exchanger.

The outdoor device may further include a four-way valve for transferring the refrigerant passing through the discharge valve to the outdoor heat exchanger or to the indoor heat exchanger.

A plurality of indoor heat exchangers may be provided, and each indoor heat exchanger may be connected in parallel.

A first hot water supply expansion valve may be installed at a rear end of a branch point of the second hot water supply discharge pipe in the first hot water supply discharge pipe.

In the hot water supply and cooling operation mode, either the hot water supply heat exchanger or the outdoor heat exchanger may operate as a condenser, or the hot water supply heat exchanger and the outdoor heat exchanger may operate as a condenser.

In the hot water supply and cooling operation mode, one of the first hot water supply expansion valve and the second hot water supply expansion valve may be opened and the other may be blocked or closed.

In the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank is the reference temperature or less and when the cooling load is lower than the reference value, the first hot water supply expansion valve may be opened, and the second hot water supply expansion valve may be blocked or closed.

In the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank is the reference temperature or less, and when the cooling load is lower than the reference value, only the hot water supply heat exchanger may operate as a condenser.

In the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank is the reference temperature or less, and when the cooling load is higher than the reference value, the second hot water supply expansion valve may be opened, and the first hot water supply expansion valve may be blocked or closed.

In the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank is the reference temperature or less, and when the cooling load is higher than the reference value, the hot water supply heat exchanger and the outdoor heat exchanger may operate as condensers.

In the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank is the reference temperature or more, and when the cooling load is higher than the reference value, the second hot water supply expansion valve may be opened, and the first hot water supply expansion valve may be blocked or closed.

In the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank is the reference temperature or more, and when the cooling load is higher than the reference value, the hot water supply heat exchanger and the outdoor heat exchanger may operate as condensers.

In the hot water supply and cooling operation mode, even if the temperature of the water accommodated in the water tank is the reference temperature or more, and when the cooling load is higher than the reference value, the first hot water supply expansion valve may be opened or the second hot water supply expansion valve may be opened according to the discharge the superheating degree of the compressor.

In the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank is the reference temperature or more, and when the cooling load is lower than the reference value, only the outdoor heat exchanger may operate. as a condenser.

In the hot water supply and cooling operation mode, when the temperature of the water accommodated in the water tank is the reference temperature or more, and when the cooling load is lower than the reference value, the water tank may be heated by a separate heater.

Details of other embodiments are included in the description and drawings.

It will be understood that when an element or layer is referred to as being “on” another element or layer, the element or layer can be directly on another element or layer or intervening elements or layers. In contrast, when an element is referred to as being “directly on” another element or layer, there are no intervening elements or layers present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section could be termed a second element, component, region, layer or section without departing from the teachings.

Spatially relative terms, such as “lower”, “upper” and the like, may be used herein for ease of description to describe the relationship of one element or feature to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “lower” relative to other elements or features would then be oriented “upper” relative to the other elements or features. Thus, the exemplary term “lower” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Embodiments are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments (and intermediate structures). As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 

What is claimed is:
 1. A hybrid multi-air conditioning system, comprising: a hot water supply unit including a hot water supply heat exchanger that exchanges heat between a refrigerant and water accommodated in a water tank and a first hot water supply expansion valve that blocks or allows refrigerant condensed in the hot water supply heat exchanger to flow through a first hot water supply discharge pipe; at least one indoor device installed indoors and including at least one indoor heat exchanger and at least one indoor expansion valve; an outdoor device connected to the at least one indoor device and the hot water supply unit through a refrigerant pipe and including an outdoor heat exchanger, a compressor, and an outdoor expansion valve; a second hot water supply discharge pipe having a first side branched from the first hot water supply discharge pipe, which connects the hot water supply heat exchanger and the indoor heat exchanger, and a second side that joins a first discharge pipe, which connects the compressor and the outdoor heat exchanger; and a second hot water supply expansion valve installed on the second hot water supply discharge pipe.
 2. The hybrid multi-air conditioning system of claim 1, further comprising: at least one of a first temperature sensor that detects a water temperature in the water tank or a second temperature sensor installed at a rear end of the compressor.
 3. The hybrid multi-air conditioning system of claim 1, further comprising: a first pressure sensor installed at a rear end of the compressor.
 4. The hybrid multi-air conditioning system of claim 1, wherein the hot water supply heat exchanger is wound around an outer wall of the water tank in a coil form and exchanges heat between the refrigerant and water while the refrigerant flows inside of the hot water supply heat exchanger.
 5. The hybrid multi-air conditioning system of claim 1, wherein the outdoor device includes: a hot water supply valve that allows compressed refrigerant from the compressor to flow to the hot water supply unit; a discharge valve that allows the compressed refrigerant from the compressor to flow to the outdoor heat exchanger or the indoor heat exchanger; and a four-way valve that allows the refrigerant passing through the discharge valve to flow to the outdoor heat exchanger or to the indoor heat exchanger.
 6. The hybrid multi-air conditioning system of claim 1, wherein the at least one indoor heat exchanger comprises a plurality of indoor heat exchangers connected in parallel.
 7. The hybrid multi-air conditioning system of claim 1, wherein the first hot water supply expansion valve is installed downstream of a branch point of the second hot water supply discharge pipe from the first hot water supply discharge pipe.
 8. The hybrid multi-air conditioning system of claim 7, wherein in a hot water supply and cooling operation mode, either the hot water supply heat exchanger or the at least one outdoor heat exchanger operates as a condenser, or the hot water supply heat exchanger and the at least one outdoor heat exchanger operate as a condenser.
 9. The hybrid multi-air conditioning system of claim 7, wherein in a hot water supply and cooling operation mode, one of the first hot water supply expansion valve or the second hot water supply expansion valve is opened and the other is closed.
 10. The hybrid multi-air conditioning system of claim 9, wherein in the hot water supply and cooling operation mode, when a temperature of water accommodated in the water tank is a reference temperature or less and when a cooling load is lower than a reference value, the first hot water supply expansion valve is opened and the second hot water supply expansion valve is closed.
 11. The hybrid multi-air conditioning system of claim 9, wherein in the hot water supply and cooling operation mode, when a temperature of water accommodated in the water tank is a reference temperature or less, and when a cooling load is lower than a reference value, only the hot water supply heat exchanger operates as a condenser.
 12. The hybrid multi-air conditioning system of claim 9, wherein in the hot water supply and cooling operation mode, when a temperature of water accommodated in the water tank is a reference temperature or less, and when a cooling load is higher than a reference value, the second hot water supply expansion valve is opened and the first hot water supply expansion valve is closed, and wherein the hot water supply heat exchanger and the outdoor heat exchanger operate as condensers.
 13. The hybrid multi-air conditioning system of claim 9, wherein in the hot water supply and cooling operation mode, when a temperature of water accommodated in the water tank is a reference temperature or more, and when a cooling load is higher than a reference value, the second hot water supply expansion valve is opened and the first hot water supply expansion valve is closed, and wherein the hot water supply heat exchanger and the outdoor heat exchanger operate as condensers.
 14. The hybrid multi-air conditioning system of claim 9, wherein in the hot water supply and cooling operation mode, even if a temperature of water accommodated in the water tank is a reference temperature or more, and when a cooling load is higher than a reference value, the first hot water supply expansion valve is opened or the second hot water supply expansion valve is opened according to a superheating degree of the compressor.
 15. The hybrid multi-air conditioning system of claim 8, wherein in the hot water supply and cooling operation mode, when a temperature of water accommodated in the water tank is a reference temperature or more, and when a cooling load is lower than the reference value, only the outdoor heat exchanger operates as a condenser, or wherein the water tank is heated by a separate heater.
 16. A hybrid multi-air conditioning system, comprising: a hot water supply unit including a hot water supply heat exchanger that exchanges heat between a refrigerant and water accommodated in a water tank and a first hot water supply expansion valve that blocks or allows refrigerant condensed in the hot water supply heat exchanger to flow through a first hot water supply discharge pipe; at least one indoor device installed indoors and including at least one indoor heat exchanger and at least one indoor expansion valve; an outdoor device connected to the at least one indoor device and the hot water supply unit through a refrigerant pipe and including an outdoor heat exchanger, a compressor, and an outdoor expansion valve; a second hot water supply discharge pipe having a first side branched from the first hot water supply discharge pipe, which connects the hot water supply heat exchanger and the indoor heat exchanger, and a second side that joins a first discharge pipe, which connects the compressor and the outdoor heat exchanger, such that the hot water supply unit and the outdoor heat exchanger are connected in series; and a second hot water supply expansion valve installed on the second hot water supply discharge pipe.
 17. The hybrid multi-air conditioning system of claim 16, wherein the first hot water supply expansion valve is installed downstream of a branch point of the second hot water supply discharge pipe from the first hot water supply discharge pipe.
 18. The hybrid multi-air conditioning system of claim 17, wherein in a hot water supply and cooling operation mode, either the hot water supply heat exchanger or the at least one outdoor heat exchanger operates as a condenser, or the hot water supply heat exchanger and the at least one outdoor heat exchanger operate as a condenser.
 19. The hybrid multi-air conditioning system of claim 17, wherein in the hot water supply and cooling operation mode, one of the first hot water supply expansion valve or the second hot water supply expansion valve is opened and the other is closed.
 20. The hybrid multi-air conditioning system of claim 17, wherein in the hot water supply and cooling operation mode, when a temperature of water accommodated in the water tank is a reference temperature or more, and when a cooling load is lower than the reference value, only the outdoor heat exchanger operates as a condenser, or wherein the water tank is heated by a separate heater. 